The U.S. Supreme Court held an unusual special session Monday to hear oral arguments on whether a sweeping campaign finance reform law passed by Congress last year is constitutional.

Monday's oral arguments set the stage for a historic Supreme Court decision later this year on how far the government can go in regulating how political money is raised and spent. The high court set the unusual early session so that it could render a judgement on the campaign finance law before the start of the 2004 presidential election year in January.

Congress passed the sweeping package of campaign finance reforms last year and it was promptly signed into law by President Bush.

The new law has two major provisions. First, it bans national political parties and candidates from raising and spending what is called "soft money." These are previously unlimited political donations that mainly come from corporations, unions and wealthy individuals that detractors say are corrupting the political system in Washington.

Second, the law restricts campaign advertising on television that either attacks or supports a candidate without identifying the group behind the ads.

Opponents of the law argued Monday that the new limits on campaign donations and the restrictions on television advertising amount to an infringement of free speech. Among those who filed suit to stop the new campaign law is Republican Senator Mitch McConnell of Kentucky. "The legislation dramatically reduces the power and influence of the parties and it seeks to quiet the voices of outside groups. I think that is really at variance with what our democracy should be about," he said.

Supporters of the law say it is the only hope of regulating the influence of powerful special interests who give massive donations to political campaigns.

Republican Senator John McCain from Arizona was one of the leaders of the reform effort in Congress. "What we are really doing is restoring those laws and closing the loopholes, which would prevent corporations and unions and large [individual] donors from contributing to campaigns," he said.

The Supreme Court ruling will set the ground rules for how campaign donations are raised and spent during the 2004 presidential election cycle that begins in mid-January with the Iowa presidential caucuses.